View Full Version : Most likely Clipping?

05-09-2010, 04:57 PM
Ok, so I have a JVC head unit (20 W RMS X4) with stock speakers on an '05 Corolla (6 speaker model; 4 speakers, 2 "tweeters"). The speakers have '17.5 W' and '6 ohms' stamped on the magnet) and I'm guessing 17.5 is RMS (at least what I read online)? So the head unit has this feature:

"Amplifier Gain Control: When you are using this head unit with factory speakers (or those rated to less than 50 watts peak), the Amplifier Gain Control can limit the amount of power being sent to those speakers. When the Amp Gain Control is set to low, the volume control ranges from 0 (minimum) to 30 (maximum). When using speakers rated higher than 50 watts peak, you can set the Amp Gain Control to high, and the volume control will range from 0 to 50. The internal amp can also be turned of when all the speakers are powered by outboard amplifiers."

I set all equalizers to 0, 'Loud' was off, etc.
I ran the 1kHz tone on repeat. It was a steady tone until I hit volume 31/50. I heard a very distinct different tone, almost like a whine. Then I tried a 750Hz tone. Same thing, once I hit 32/50 that different tone kicked in. As soon as I go back to volume 30 or below, it stops.

So my question is, was I hearing clipping? I know it's hard to tell when you can't actually hear it, but from what I read online people say you will know when it starts to clip and I'm, pretty positive it was that tone once I passed 30.

So seeing as how my speakers are rated 17.5 RMS and most likely do not have a peak power of 50W, along with the clipping I heard past volume 30, I guess I should set it to low power?

I have no problem having the volume maxed out at 30. It's still loud (for me). I just want the most out of my head unit without straining my stock speakers.


05-11-2010, 10:52 AM
Quite a few HUs do start to clip when you begin to reach 60-75% of their peak volume. It's possible yours may have just been clipping.